My radiation was EBRT. RO never stated rad or ADT as cause. I informed him of the shrinkage and also informed him that during the first month or so of Tx (Tx of radiation and ADT started together) I could feel a negative sensation in my testicles and area at different times throughout Tx. I'm still on ADT and don't necessarily feel the same sensation now. But I am remined every day that my testicles continue to shrink. Docs don't like to talk about this issue with their patients. I have heard from many Zoom or other videos by Urologists/oncologists, that you have to use it or you lose it. Same thing with guys on this site, one should attempt to get an erection regularly to keep the signal going down there.